Method of improving the dye receptivity of fibers of vinylidene cyanide copolymers



United States Patent 01 ice Patented June 18, 1968 ABSTRAQT OF THE DISCLOSURE A method for producing vinylidene cyanide copolymer fibers of superior dye receptivity wherein the fibers are produced by extruding a spinning solution of vinylidene cyanide copolymer into a coagulation bath containing a minor amount of a polyoxyalkylene glycol and/or fatty acid esters of polyoxyalkylene glycols. The vinylidene cyanide copolymer spinning solution preferably utilizes a solvent comprised of a major proportion of acetonitrile in a minor proportion of water and the coagulation bath preferably utilizes a major proportion of water and a minor proportion of acetonitrile in addition to the minor proportion of polyoxyalkylene material.

This invention relates to synthetic fibers exhibiting improved dye receptivity and to a method of preparing the same. More particularly, this invention relates to vinylidene cyanide copolymer fibers having superior dye receptivity, such fibers having been prepared by extruding a spinning solution containing vinylidene cyanide copolymer into a coagulating bath containing a minor amount of a material selected from the group consisting of polyoxyalkylene glycols and fatty acid esters of polyoxyalkylene glycols, to thereby wet-spin fibers from such spinning solutions.

Synthetic resinous copolymers of vinylidene cyanide and another monomer copoly-merizable therewith are known to present valuable fibenforming characteristics. However, heretofore the resulting fibers have been difiicult to dye satisfactorily, e.g., the percent dye uptake by the fibers has been undesirably low.

The resinous copolymers of vinylidene cyanide which are contemplated herein generally contain in excess of about 45% of vinylidene cyanide (methylene malononitrile or vinylidene dinitrile) units copolymerized with one or more ethylenically unsaturated monomers such as vinyl acetate or the like, as described in US. Patents 2,615,865 through 2,615,880, inclusive, 2,628,954, 2,650,911, 2,654,- 724, 2,654,728, 2,657,197, 2,716,104, 2,716,105, 2,716,106, and 2,740,769 and Canadian Patent No. 569,262.

The copolymers usually comprise units of vinylidene wherein Ar is an aromatic radical in which all the hydrogen atoms are attached to carbon atoms, such as vinyl benzoate; homologs of vinyl benzoate of the formula wherein each R is a member of the class consisting of hydrogen atoms or lower alkyl radicals, for example, vinyl toluate and the like; monomers of the above general class wherein the aromatic radical is halogen substituted, such as vinyl p-chlorobenzoate, vinyl o-chlorobenzoate, vinyl m-chlorobenzoate, and similar vinyl halobenzoates and monomers of the above general class wherein the aromatic radical is alkoxy substituted, for example, vinyl p-methoxybenzoate, vinyl o-methoxybenzoate and vinyl p-ethoxybenzoate. The copolymerization with vinylidene cyanide, of such monomers, and the resulting copolymers are disclosed in US. Patent 2,615,867, issued Oct. 28, 1952.

(3) Styrene and substituted styrenes of the general formula wherein Ar is an aromatic radical in which all of the hydrogen atoms are attached to carbon. atoms and R is a member of the class consisting of hydrogen atoms and alkyl radicals, preferably those which contain from 1 to 4 carbon atoms, such as styrene itself, and substituted styrenes such as alpha-methyl styrene, alpha-ethyl styrene, alpha-butyl styrene, alpha-chlorostyrene, alpha-bromostyrene, 2,5-dichlorostyrene, 2,5-dibromostyrene, ortho-, rneta-, and paramethoxystyrene, paraalpha-dimethyl styrene, paramethyl styrene, 3,4-dichlorostyrene, 3,4-difluorostyrene, 2,4-dichlorostyrene, 2,4,5-trichlorostyrene, dichloromonofluorostyrenes and the like. Copolymerization of vinylidene cyanide with styrene and substituted styrenes is disclosed in US. Patent 2,615,868, issued Oct. 28, 1952;

(4) Olefins of the general structure cm: R

wherein R is an alkyl radical, preferably containing from 1 to 6 carbon atoms, such as isobutylene, Z-methyl propane-1, Z-methyl-butene-l, 2-methylpentene-1, 2,3-dimethylbutene-l, 2,3-dimethyl-pentene-1, 2,3,3-trimethylbutene-l, 2,3,4-trimethylpentene-1, 2,6dimethyloctene-l, Z-methylnonadecene-l, and the like. Copolymerization of such olefins with vinylidene cyanide is disclosed in US. Patent 2,615,865, issued Oct. 28, 1952;

(5) Alkyl esters of methacrylic acid which possess the structure wherein R is an alkyl radical, preferably containing from 1 to 8 carbon atoms, for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacryllate, heptyl methacrylate, octyl rnethacrylate, decyl methacrylate, and the like. Vinylidene cyanide/alkyl methacrylate copolymers and their preparation are disclosed in US. Patent 2,615,- 871, issued Oct. 28, 1952;

(6) 2-ha1ogenated monoolefins of the structure wherein R is a lower alkyl radical such as methyl, ethyl, propyl or butyl, and Y is a halogen atom, such as 2-chloropropene, 2-chlorobutene, 2-chloropentene, 2-chlorohexene, 2-c-hloroheptene, 2-bromobutene, 2-bromoheptenc, 2-fluorohexene, 2-fluorobutene, 2-iodopropene, 2-iodopentene, and the like. Copolymerization of these compounds with vinylidene cyanide is disclosed in US. Patent 2,615,877, issued October 28, 1952;

(7) Isopropenyl esters of organic monocarboxylic acids, preferably of the formula RCOOH, wherein R is an alkyl radical containing from 1 to 6 carbon atoms, and including isopropenyl acetate, isopropenyl propionate, isopropenyl isobutyrate, isopropenyl valerate, isopropenyl caproate, and isopropenyl enanthate; as well as isopropenyl esters of aromatic carboxylic acids, for example, isopropenyl benzoate, isopropenyl p-chlorobenzoate, isopropenyl o-chlorobenzoate, isopropenyl m-chlorobenzoate, isopropenyl toluate, isopropenyl alpha-chloroacetate, isopropenyl alpha-bromopropionate, and the like; the copolymerization of all of which with vinylidene cyanide is described in US. Patent 2,615,875, issued Oct. 28, 1952;

(8) Vinyl esters of alpha-halo saturated aliphatic monocarboxylic acids of the structure wherein R is a member of the class consisting of hydrogen and an alkyl radical, preferably a lower alkyl radical, and Y is a halogen atom, such as vinyl alpha-chloroacetate, vinyl alpha-bromoacetate, vinyl alpha-iodopropionate, vinyl alpha-bromovalerate and the like. The copolymerization of such monomers with vinylidene cyanide is described in US. Patent 2,615,876, issued Oct. 28, 1952.

(9) Vinyl halides such as vinyl chloride, vinyl bromide and the like, which are copolymerized with vinylidene cyanide as described in US. Patent 2,615,869, issued Oct. 28, 1952.

In addition to interpolymers of vinylidene cyanide containing the essentially l to 1 molar alternating structure and essentially 50 mol percent vinylidene cyanide units, such as those disclosed in the patents referred to above, other vinylidene cyanide interpolymers have been described. For example, there are included interpolymers, of

this vinylidene cyanide content, made from vinylidene cyanide and more than one copolymerizable monoolefinic compound, at least one of which forms an essentially 1:1 alternating copolymer when copolymerized with vinylidene cyanide, a large number of which interpolymers are disclosed in US. Patent 2,716,106.

Other polymerizable monoolefinic compounds form interpolymers with vinylidene cyanide, in addition to those set out above including, by way of example, the following classes of compounds:

Monoolefinic hydrocarbons, such as 2,3-dimethylhexene-l; 2,3,4-trimethyl-pentene-l; ethylene; propylene; butylene; amylene; hexylene and the like;

Esters of unsaturated acids other than methacrylic, e. g., of acrylic acid and tiglic acid such as methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, amyl acrylate, 3,5,5-trimethylhexyl acrylate, dodecyl acrylate and ethyl tiglate.

Allyl and substituted allyl esters such as allyl chloride, allyl cyanide, allyl bromide, allyl fluoride, allyl iodide, allyl nitrate, allyl thiocyanate, allyl butyrate, allyl benzoate, allyl 3,5,5-trimethyl hexoate, allyl lactate, allyl pyruvate, allyl acetoacetate, allyl thioacetate, as well as methallyl esters corresponding to the above allyl esters as well as esters from such alkenyl alcohols as betaethyl allyl alcohol, beta-propyl allyl alcohol, and 1-butene-4-ol;

Esters of substituted acrylic acids, such as methyl alphachloroacrylate, methyl alpha-bromoacrylate, ethyl alphachloroacrylate, propyl alpha-chloroacrylate, amyl alphachloroacrylate, 3,5,5-trimethyl hexyl alpha-chloroacrylate and decyl alpha-cyanoacrylate;

Esters of monoethylenically unsaturated dicarboxylic acids, such as dimethyl maleate, diethyl maleate, dimethyl fumarate and diethyl fumarate;

Monoolefinically unsaturated organic nitriles such as acrylonitrile, methacrylonitrile, 1,1-dicyanopropene-l, crotonitrile, oleonitrile and the like;

Monoolefinically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, butenoic acid, angelic acid, tiglic acid and the like;

Of these vinylidene cyanide copolymers a particularly useful copolymer which can readily be converted to filaments of excellent physical properties is the copolymer of vinylidene cyanide and vinyl acetate preferably consisting essentially of a regular structure of alternated units of the monomers, i.e., approximately 50 mol percent of each.

To improve the dyeability of the resultant fibers, the monomers making up the vinylidene cyanide copolymer may be copolymerized along with sufficient amount of an ethylenically unsaturated organic sulfonic acid to produce a copolymer containing about 0.15 to 2 mol percent of the sulfonic acid component.

Representative sulfonic acids which may be employed include styrene sulfonic acids such as ortho-, metaor parastyrene sulfonic acid as well as commercial mixtures thereof, ortho-, metaor para-sulfomethyl styrene, mixtures thereof, substitution products thereof such as polysulfo derivatives as well as ,B-sulfoethyl methacrylate (isethionic acid ester of methacrylic acid), sulfonic acids wherein the sulfo group is less than three atoms removed from the ethylenic unsaturation, e.g., vinylsulfonic acid, aliylsulfonic acid, methallyl sulfonic acid and the like.

It is frequently desirable to employ a mixture of more than one of the foregoing vinylidene cyanide polymers in order to form fibers, e.g., a mixture of a copolymer of vinylidene cyanide and vinyl acetate and a terpolymer of vinylidene cyanide, vinyl acetate and an ethylenically unsaturated sulfonic acid or a salt thereof such as a styrene sulfonic acid or potassium styrene sulfonate. The fibers may also contain various additives in addition to the vinylidene cyanide polymer or polymers, e.g., a polymer of N,N-dimethyl acrylamide, a copolymer of N,N- dimethyl acrylamide and vinyl acetate, and so forth.

As is well known in the art, copolymers of vinylidene cyanide have particular application in the formation of fibers and generally are wet spun in order to produce such fibers.

It is an object of the present invention to provide a novel method for improving the dye receptivity of vinylidene cyanide copolymer fibers.

Another object is to provide vinylidene cyanide copolymer fibers exhibiting a superior affinity and receptivity for dyes.

Other objects and the advantages of this invention will become apparent from the discussion that appears hereinafter.

In accordance with one aspect of this invention, a spinning solution of a vinylidene cyanide copolymer is extruded through a shaped orifice into a coagulating bath which contains a minor amount of a material selected from the group consisting of polyoxyalkylene glycols and fatty acid esters of polyoxyalkylene glycols. This results in a coagulation of vinylidene cyanide copolymer fibers from the spinning solution, which fibers contain therein a minor amount of the polyoxyalkylene glycol or fatty acid ester thereof. Generally, the fiber while still in the coagulating bath, is subjected to a drawing operation, which may be followed by stretching, to provide orientation and improve the mechanical characteristics of the fiber.

The solvent employed for the vinylidene cyanide copolymer is generally a mixture of acetonitrile and water. The spinning solution solvent will usually preponderate in acetonitrile, whereas the coagulating bath will preponderate in water. For example, the spinning solution the addition of 1% of each of the materials listed in the following table. The resulting fibers were found to take up the indicated quantities of the disperse dye, Pink BA (Celliton Fast Pink BA-CF, General Dyestuff Co., N.Y.), after immersion for 1 hour at 97 C. of a 100 mg.

solvent mixture generally contains at least about 75 per- 5 portion of fiber in 600 ml. of an aqueous solution concent acetonitrile, and preferably from about 84 to 86 laining 300 mg. of dye. The table also includes the solupel'cent acetonitrile and correspondingly from about 16 bility behavior observed on mixing approximately 0.5 g. to 14 percent water. The coagulating bath, on the other of each additive with about 2 ml. of water or acetonitrile.

Additive Solubility Dye Uptake Bath Additive (Percent Pink In Water In Acetonitrile BA in fiber) None 0. 74 Polyoxyalkylcnc Glycol, avg. molecular Soluble room temperature Soluble room temperature 1.10

weight 2,900 (40% ethylene oxide, 60% propylene oxide). Polyoxyethylene glycol laurate Dispersed hot-not dissolved ,do 1. 48 Polyoxyethylene glycol stearate .do Soluble 60 C 1. 52

hand, will ordinarily contain at least 55 percent water, The foregoing clearly demonstrates the improvement in and preferably will contain from' about 62 to 80 percent dye pick-up when a polyoxyalkylene material is present water and correspondingly from about 38 to percent 20 in the coagulating bath as compared to a control whereacetonitrile. in the bath contains no such material.

The polyoxyalkylene materials employed in the method Any departure from the above description which conof our invention generally are more readily soluble in forms to the present invention is intended to be included acetonitrile than in water. Such materials nevertheless Within the scope of the invention as defined by the followhave sufficient affinity for water that they will be present ing claims. in significant concentration at the interface between the Having thus described our invention, what we desire to extruded fiber from the spinning solution and the coagusecure and claim by Letters Patent is; lating bath, and hence will be taken up by and will be 1. A method of improving the dye-receptivity of vinylprescnt in the resulting coagulated vinylidene cyanide coidem cyanide copolymfif fibers, this method Comprising polymer fiber extruding a solution of vinylidene cyanide copolymer con- If a polyoxyalkylene glycol i l d, it i typically taining more than about percent vinylidene cyanide prepared by condensation of an alkylene oxide, e.g., through a Shaped Orifice and into a coagulating bath ethylene oxide and/0r propylene oxide, with an alkylene lining a minor amount of P y y y material glycol such as ethylene glycol, propylene glycol, or the lected from the g p Consisting of p y y y s ylike. The polyoxyalkylene glycol should desirably have a 30 C015 and fatty acld fisters 0f P y y y g y to molecular weight of from about 200 to 3,000. thereby form and coagulate 831d b In accordance with a preferred aspect of our invention, I\he mth0d of f 1 wherein Said Polyoxyalkylene there is incorporated in the coagulating bath a fatty acid mammal 1S a fatty acid of a pf y fy y g y ester of a polyoxyalkylene glycol of the foregoing type. 0 3. The method of claim 2 whereln sal-d fatty acid con- Fatty acids which are suitable for use in preparing 4 tams from about4t 26 atom? the fatty acid esters of polyoxyalkylene glycols may be 4. The method of clalm 2 wherein sa1d fatty acid 18 either saturated or unsaturated. Suitable saturated fatty launc aCldacids desirably may contain from about 4 to 26 carbon of clalm 2 Wherem sald fatty acld atoms, a more preferred range being from about 10 to steam; acld- 18 carbon atoms. Laurie and stearic acids are particularly 45 The method of clam} 2 Wherem sald palyoxyalkylfin6 suitable. Unsaturated fatty acids include those containing glycol has a molecular of m about 200 to 9- from about 10 to about 24 carbon atoms. A preferred The method of clam} 1 Wherem the.amount said unsaturated fatty acid is oleic acid polyoxyalkylene material in said coagulating hath 18 from The amount of polyoxyalkylene material present in the about to percent welght' coagulating bath is generally from about 0.1 to 3 percent f T of clalm 1 Wherem sald Polyoxyalkylene by weight, of the bath, a more preferred range being material 13 a polyoxyanlylene 9 from about 05 to 15 percent. 1 The method of claim 8 wherein said polyoxyalkylene By virtue of the foregoing method, there result vinylg 5 2.? a i Weight of from. abput 200 to idene cyanide copolyrner fibers which have a markedly i clalm 9 Wherem the Polyoxyalkyl superior dye receptivity and dye uptake. These fibers can 3 um s o yoxyalkylene glycol are sfalected from be readily dyed with disperse dyes, as well as with acid g ggg 5332 2 2 gf gg i gggg unlts Poll/OX3" ggg g ggg s gg utlllzlns wnventwnal dyelng Commons d 11. A m hod of improving the dye receptivity of vinyl.

The following example will further illustrate this ini s gjg g gggg g g g ggi i li izli ggofigg j il ventlon. All parts are by welght unless otherwise stated. mining more than about 45 pgrcent vinyflidenfi cyanide in E l a SOlVCllbinlXtlge containing from about 100 to 80 percent 2 er, acetonitrl e an correspondingly from about 0 to 20 per 22; Z a S2 2 3 583 gi g gg g g 5 g i 10361:; water, throufgh a shaped orifice and into a coagulating dene cyanide and vinyl acetate in approximately equal g 2 8 12 g gl percefnt Water from molar proportions. This solution, which was fluid above to 3 0 erce t 1 ace and p about about 45 C., was extruded through a spinnerette containf p n O a P yqxya y ma'tenal to thereby ing 5 holes of 0.076 mm. diameter into a coagulation bath mm and coagulate vmylldene cyamde. coplflymer fibers at C., the bath being composed of 30% acetonitrile The method of clalm 11 wherein sald coagulated and 70% Water Fibers were withdrawn at 25 m/mim 7O fibers are drawn down and then subjected to stretching. after passage through 2 feet of the bath, were wound over Thmefhod of clalm 11 wherein Said P Y Y 1/ a pair of skewed rolls, were then reimmersed in the bath ene matemll 1S a fatty acid ester f a polyoxyalkylene for a 3 to 1 stretch between guides 1 foot apart, and finally y Were taken up at ;m./min. This procedure was repeated, The method f Claim 13 wherein Said fatty acid with the coagulation and stretch bath being modified by 75 contains from about 4 to 26 carbon atoms.

15. The method of claim 14 wherein said fatty acid is lauric acid.

16. The method of claim 14 wherein said fatty acid is stearic acid.

17. The method of claim 11 wherein said polyoxyalkylene material is a polyoxyalkylene glycol.

18. The method of claim 17 wherein said polyoxyalkylene glycol has a molecular weight of from about 200 to 3,000.

19. The method of claim 18 wherein the polyoxyalkylene units of said polyoxyalkylene glycol are selected from the group consisting of polyoxyethylene units, polyoxypropylene units, and mixtures thereof.

8 References Cited UNITED STATES PATENTS JAMES A. SEIDLECK, Primary Examiner.

10 A. H. BRODMERKEL, Examiner.

H. MINTZ, Assistant Examiner. 

